How to Play AVI

Familiarize yourself with how the AVI file format works. AVI is what's called a "container format," which means it doesn't specify how the video and audio contained within it was encoded. It simply "contains" the data in a shell that will be familiar to the user and to your software.

• The first step to understanding why AVI files can be so fussy is to understand what encoding and decoding are. When raw video data is saved into a computer file, it needs to be encoded. This means that it will be compressed using a certain algorithm to reduce it to a manageable size.
• To play back a video file, your media player software will have to decode the data using the same algorithm used to encode it. Basically, the data was compressed a certain way, and your computer needs to unpack it in the exact same way for it to be usable.
• Encoding and decoding is performed using a "codec." A codec, which is actually an abbreviation for "Coder / Decoder," is a small program that allows your media software to pack and unpack video files. Therefore, if you don't have the same codec that was used to make the AVI video, you won't be able to play it.

Download and install a media player packaged with many of the most common codecs. Before you try to find and install the codec you need individually, consider using a different media player. VLC is a free and open source media player that is packaged with a huge assortment of common codecs. Install VLC and then try to use it to open your video file. If the file plays, then the codec needed was provided by VLC.

Download an install an all-purpose codec. If VLC won't play your file, you can try downloading a single codec called FFDSHOW (which is also free and open source). FFDSHOW is a codec that can pack and unpack a variety of different media files, so there's a good chance it can handle the decoding for your troublesome AVI file. Simply download the codec and double-click the executable file to begin the installation wizard.

Download and install a codec pack. A codec pack is exactly what it sounds like: a package containing hundreds of codecs. If you still can't play your AVI file, you can download a codec pack in hopes that 1 of the codecs included will be able to decode your file. This should be treated as a backup plan, however, because it represents a serious waste of system resources; you'll be installing hundreds of codecs that you'll never use. Some popular codec packs are K-Lite Codec Pack, XP Codec Pack, and Cole2K Media Codec Pack.